Loading CSS from a string in Ruby with Faraday

In this guide, we'll show you how to load custom CSS as a given string when converting an HTML document to PDF using PDFShift's API. This allows you to add custom CSS to your page to customize the output of your generated PDF.

It can be interesting to be able to set a custom CSS value to adjust the rendering of your page specifically when exporting the document to PDF. This allows you to keep a standard look and feel to your users, but adjust some areas when sending that same document to PDFShift to get back a PDF.

require 'faraday'
require 'json'

# You can get an API key at https://pdfshift.io
api_key = 'sk_xxxxxxxxxxxx'

params = {
    'source' => 'https://www.example.com',
    'css' => 'body { background-color: #f00; }'
}

# Create a Faraday connection
conn = Faraday.new(url: "https://api.pdfshift.io/v3/convert/pdf") do |faraday|
    faraday.request :url_encoded
    faraday.adapter Faraday.default_adapter
end

# Make the POST request
response = conn.post do |req|
    req.headers['Content-Type'] = 'application/json'
    req.headers['Authorization'] = "Basic #{Base64.strict_encode64("api:#{api_key}")}"
    req.body = params.to_json
end

# Check for successful response
unless response.success?
    raise "Request failed with status code #{response.status}: #{response.body}"
end

# write response to a file nammed "result.pdf"
File.open('result.pdf', 'wb') { |f| f.write(response.body) }

# Print a success message
puts 'The PDF document was generated and saved to result.pdf'

The css parameter accepts either a string or a URL. It will be used as the CSS for the page when converting it to PDF. This allows you to set a custom CSS value to adjust the rendering of your page specifically when exporting the document to PDF.

For further details on the css property and its usage, please refer to our dedicated documentation.

We hope this guide was helpful. If you have any questions or noticed any issues on the code above,
feel free to drop us a line.